You may have found a new bug if it only involves dbids of more than 9 digits.
Here are some prior (but unanswered or not fully answered) discussions regarding AWR/ASH dbids:
You should describe exactly what you are doing and add a screen shot so all can see what you are seeing.
I am having the exact problem as stated in the thread:
As in the screenshot, I am unable to change DBID to correct one for running an ASH report, but I can change to the first 3 perhaps because they are 9 numbers long..
Hopefully someone on the development team will see this and comment / log a bug. Otherwise, if you are able, log an SR with MOS.